Typewriter carriage return



June 23, 1959 H. WUSTYENEY ETI'AL 5 I TYPEWRITER CARRIAGE RETURN Filedon. so, 1956 United States Patent 'I -YPEWRITER Herbert Wiisteney,Munich, and Hans-Jiirgen Richter, Berlin Frohn'au, Germany, assignors toSiemens & Halske Aktiengesellschaft, Berlin and Munich, Germany, acorporation of Germany Application October 30', 1956, Serial No. 619,334

Claims priority applicafionGermany November 4,. 1955 14 Claims; (Cl.197-68) This invention is concerned with a device comprising springactuated means for returning to the line-start position the carriage ofa typewriter, especially ateleprinter machine. The term typewriter isintended to means ofiice typewriters as well as teleprinter machinesofall kinds,- operating. with sheet records.-

It is customary in teleprinter machines and in some motor-controlledoffice machines operating with sheet records, to effect the carriagereturn from the end of lines or, for example, atthe end of paragraphs,from a desired line position, by spring means inwhich power is storedduring the typing operation, The carriage return is effected byreleasing the stored spring. power in response to a carriage-returnsignal, for example, responsive to depression of a return key.. In.teleprinter machines there isavailable the same time interval for theprinting. as well as for other. functions, such as lower to upper caseand numeral shifting, namely, the time interval required. for thetransmission of a symbol. It is customary in eifecting the carriagereturn, to add to this time interval the transmission time for anothersymbol so as to effect the line advance. Thisv time, amounting to twosymbol intervals, is-however, quite short, especiallywhenhigh typingspeeds are demanded or in the presence of other conditions, for example,an unfavorable inclined position of the machine that makes the carriagereturn difficult. In such cases, there. arises the danger that the nextfollowing, symbol is. lost or that other errors are made.-

It isknown to use. a strong spring for effecting the carriage return andto uncouple such spring from the carriage during the typing operation;however, an additional expenditure. for the coupling and complicatedcontrol means as Well as a device for winding the return spring arenecessary to meet the corresponding requirements.

These drawbacks are. according to the invention avoided by the provisionof an. auxiliary motor. for supporting. or. augmenting. in the presenceof. certain unfavorable operating conditions. the. actuation of thecustomarily employed spring. means in which power is stored during the.typing or printing operation.

In accordance. with another feature of the invention, the auxiliarymotor is automatically connectable. for operation. for the whole. or fora selectable portion of the carriage return. path depending upon theincline at which the machine may be disposed to the horizontal. Theauxiliary motor is preferably an asynchronous fractional horse-powermotor and may be permanently connected for operation with the carriage.

The operative connection of the auxiliary motor is in accordance with afurtherfeature of the invention effected depending upon the actuationofa carriage-return pull rod The disconnection of the auxiliary motor iseffected shortly before the carriage reaches the line-start position inorder to avoid hard impact upon a corresponding stop. In machineshaving, for example, a pneumatic shock 2,891,651 Patented June 23, 1 9592. absorber for the carriage, the disconnection of the auxiliary motortakes place shortly before or shortly after contact is made with theyieldable shock absorber buffer, by an element which is shiftaib-le withthe carriage and which controls, for example, a switch.

In case the auxiliary motor is used for operation depending upon theinclined position of the machine, there is provided in accordance withstill another feature, a mercury switch with its-tube disposed inclinedto a plane extending, in parallel to the direction of the carriagemotion, so that such switch is in circuit closing position only inpredetermined positions of the carriage with respect to the horizontal.

The foregoing and other objects and features will appear from thedescription which will be rendered below with reference to theaccompanying drawing showing in schematic representation an example ofthe invention.

Referring, now to the drawing, the carriage 2' of a sheet recordteleprinter machine, carrying a platen or drum 1, is in known mannerconnected by a belt 3 with a rotatable reel 4 enclosing a spiral spring.Fixedly connected with the reel 4 is a gear wheel 5' which meshes withan intermediate gear wheel 6 driven by a pinion 8 operated by a smallfractional horse-power asynchronous motor 7. The three gear wheels 5, 6,8 are always in mesh.

The advance of the carriage 2 to the left is effected by'customary'means (not shown) during the writing or typing operation. The return ofthe carriage by the force of the spring contained in the reel 4 isprevented by a locking pawl 9 which is spring-connected to a ratchet 10moving with the carriage 2. Coupled with this pawl 9 is a pull rod 11which is operatively controlled in response to receipt of acarriage-return signal.

The circuit for the asynchronous auxiliary motor 7 extends from aterminal of an alternating current source over a switch 12' which willbe closed upon actuation of the carriage-return pull rod 11-, thenceover another switch 14 which is normally closed but may be opened by abracket member 13 moving with the carriage 2', and finally over. amercury switch 15 to a terminal of the motor 7 and from there back tothecurrent source.

A pneumatic shock absorber 16 is provided, the carriage 2 having amember 2a for engaging. a shock absorber buffer 17 incident to-thecarriage return.

The tube of the mercury switch 15 is disposed at an incline to a planeextending in parallel to the direction of the carriage-return, so thatsuch switch will be closed only when the carriage-returnis along ahorizontal plane or in a position relative to the horizontal, in whichits return is impeded.

The operation is as follows:

The spiral spring enclosed in the reel 4 is tensioned during the typingor writing operation during which the carriage is moved to the left,pulling. the belt 3 and accordingly rotating the reel 4. The gear wheels5, 6 and 8 thereby rotate the motor shaft in an idling operation. Itshall be assumed that the direction of motion of the carriage is along ahorizontal plane. The mercury switch is accordingly closed.

The pull rod 11 will be actuated responsive to receipt of acarriage-return teleprinter signal and the locking pawl 9 will be pulleddownward, freeing the ratchet 10 and at. the same time closing contact121 The switches 14 and 15 are at that instant in closed position, andthe motor 7 will accordingly operate and augment the force of the springin the casing 4 to effect return of the carriage 2 in the direction WRwith high speed.

Even if. the machine should be in an inclined position in which thecarriagereturn is impeded by gravity, the return of the carriage can beeffected by means. of the device just described, in such a short time asto exclude disturbance of the teleprinter operation. The pull rod 11 andthe locking pawl 9 may be locked in operated position by suitable means(not shown) and the contact 12 may thus be held in actuated position.

Shortly before the carriage reaches the position corresponding to theline start, the bracket member 13 will open the contact 14; immediatelyafterwards, the stop 2a of the carriage 2 will engage the butter 17 ofthe shock absorber 16. The carriage return is thereby in its terminalphase delayed to such an extent that a harsh impact of the carriage onthe stop associated with the line-start is prevented.

It has been assumed in the described example, that the return spring hasa force required by teleprinter machines provided for operation only inhorizontal position. The spiral spring contained in the reel 4 must alsorotate the motor shaft and the load thereon is accordingly greater thanin a machine without an auxiliary motor. The mercury switch isaccordingly so disposed that it will be in disconnect position only whenthe direction of motion of the carriage is in a plane in which the forceof gravity supports the carriage return.

The use of an asynchronous motor has the advantage that itscharacteristic may be such as to avoid excessive carriage return speed.Another advantage resides in low radio interference voltages.

In using an electric motor as an auxiliary motor and when highrequirements are posed with regard to freedom from radio interference,the switches used may be combined in a single switch and such switch maybe mechanically controlled from several points. The corresponding switchmay in such case be in a casing which is common to the motor.

In employing the described arrangement with the mercury switch,depending upon the inclined position of the direction of the carriagemotion, the use of the corresponding typewriter in an airplane or othervehicle may result with regard to the angular acceleration of thecorrect incline in an identical effect, simulating a horizontalposition. In other cases, however, there will result an effect ininclined position in stationary operation. The arrangement isaccordingly advantageous in either case.

In place of the spring-tensioning belt and the spiral spring described,other spring means may be used within the scope of the invention. Theauxiliary motor may likewise be different; for example, it may be apneumatic motor, and the shock absorber may cooperate with a controlvalve.

Changes may be made within the scope and spirit of the appended claims.

We claim:

1. A power-driven typewriter comprising a carriage which is advancedduring the typing operation, a carriagereturn spring, means controlledby said carriage for tensioning said spring step-by-step during theadvance thereof so as to store in said spring power, to be utilized forreturning said carriage from an advanced position to linestart position,an auxiliary motor, and means controlled by said motor, actingindependently of, but augmenting the power stored in said spring for thepurpose of securing return of said carriage.

2v A power-driven typewriter comprising a carriage which is advancedduring the typing operation, a carriagereturn spring, means controlledby said carriage for tensioning said spring step-by-step during theadvance thereof so as to store in said spring power, to be utilized forreturning said carriage from an advanced position to linestart position,an auxiliary motor, means controlled by said motor for augmenting thepower stored in said spring for the purpose of securing return of saidcarriage, and means depending upon predetermined inclination of thecarriage path to the horizontal for automatically connecting saidauxiliary motor for operation for at least a selectably determinableportion of said return path.

3. A power-driven typewriter comprising a carriage which is advancedduring the typing operation, a carriagereturn spring, means controlledby said carriage for tensioning said spring step-by-step during theadvance thereof so as to store in said spring power, to be utilized forreturning said carriage from an advanced position to line-startposition, an auxiliary motor, means controlled by said motor foraugmenting the power stored in said spring for the purpose of securingreturn of said carriage, and means for automatically connecting saidauxiliary motor for operation when said carriage return path extendshorizontally and in predetermined inclination to the horizontal,respectively.

4. A power-driven typewriter comprising a carriage which is advancedduring the typing operation, a carriagereturn spring, means controlledby said carriage for tensioning said spring step-by-step during theadvance thereof so as to store in said spring power, to be utilized forreturning said carriage from an advanced position to linestart position,an auxiliary motor, means controlled by said motor for augmenting thepower stored in said spring for the purpose of securing return of saidcarriage, a rotatable casing containing said spring, and means forpermanently connecting the shaft of said auxiliary motor for drivingcoaction with said casing.

5. A power-driven typewriter comprising a carriage which is advancedduring the typing operation, a carriage-return spring, means controlledby said carriage for tensioning said spring step-by-step during theadvance thereof so as to store in said spring power, to be utilized forreturning said carriage from an advanced position to line-startposition, an auxiliary motor, means controlled by said motor foraugmenting the power stored in said spring for the purpose of securingreturn of said carriage, a rotatable casing containing said spring, andgear means for permanently connecting the shaft of said auxiliary motorfor driving coaction with said casing.

6. A power-driven typewriter comprising a carriage which is advancedduring the typing operation, a carriage-return spring, means controlledby said carriage for tensioning said spring step-by-step during the ad-Vance thereof so as to store in said spring power, to be utilized forreturning said carriage from an advanced position to line-startposition, an auxiliary motor, means controlled by said motor foraugmenting the power stored in said spring for the purpose of securingreturn of said carriage, and a circuit for actuating said auxiliarymotor, said circuit including a mercury switch having a switching tubedisposed at a predetermined incline to the horizontal for automaticallyclosing said cir cuit to actuate said auxiliary motor only inpredetermined positions of said carriage with respect to the horizontal.

7. A power-driven typewriter comprising a carriage which is advancedduring the typing operation, a carriage-return spring, means controlledby said carriage for tensioning said spring step-by-step during theadvance thereof so as to store in said spring power, to be utilized forreturning said carriage from an advanced position to line-startposition, an auxiliary motor, means controlled by said motor foraugmenting the power stored in said spring for the purpose of securingreturn of said carriage, circuit means for automatically connecting saidauxiliary motor for operation depending upon predetermined inclinationof said carriage to the horizontal, and means actuated by said carriagefor opening said circuit means to disconnect said auxiliary motor at aninstant when said carriage has reached a predetermined point in thereturn motion thereof.

8. A power-driven typewriter comprising a carriage which is advancedduring the typing operation, a carriage-return spring, means controlledby said carriage for tensioning said spring step-by-step during theadvance thereof so as to store in said spring power, to be utilized forreturning said carriage from an advanced position to line-startposition, an auxiliary motor, means controlled by said motor foraugmenting the power stored in said spring for the purpose of securingreturn of said carriage, means for automatically connecting saidauxiliary motor for operation depending upon predetermined inclinationof said carriage to the horizontal so as to augment the force stored insaid spring in returning said carriage to line-start position, a shockabsorber having a yieldable bufier extending therefrom for engagement bya part of said carriage at the conclusion of the return thereof intoline-start position, and means actuated by said carriage for openingsaid circuit means to disconnect said auxiliary motor at an instant whensaid part of said carriage is in predetermined position with respect tosaid butter.

9. A power-driven typewriter comprising a carriage which is advancedduring the typing operation, a carriage-return spring, means controlledby said carriage for tensioning said spring step-by-step during theadvance thereof so as to store in said spring power, to be utilized forreturning said carriage from an advanced position to line-startposition, an auxiliary motor, means controlled by said motor foraugmenting the power stored in said spring for the purpose of securingreturn of said carriage, circuit means for automatically connecting saidauxiliary motor for operation depending upon predetermined inclinationof said carriage to the horizontal so as to augment the force stored insaid spring in returning said carriage to line-start position, a shockabsorber having a yieldable buffer extending therefrom for engagement bya part of said carriage at the conclusion of the return thereof intoline-start position, and means actuated by said carriage for openingsaid circuit means to disconnect said auxiliary motor at an instantprior to engagement of said part of said carriage with said buffer.

10. A power-driven typewriter comprising a carriage which is advancedduring the typing operation, a carriage-return spring, means controlledby said carriage for tensioning said spring step-by-step during theadvance thereof so as to store in said spring power, to be utilized forreturning said carriage from an advanced position to line-startposition, an auxiliary motor, means controlled by said motor foraugmenting the power stored in said spring for the purpose of securingreturn of said carriage, circuit means for automatically connecting saidauxiliary motor for operation depending upon predetermined inclinationof said carriage to the horizontal so as to augment the force stored insaid spring in returning said carriage to line-start position, a shockabsorber having a yieldable buffer extending therefrom for engagement bya part of said carriage at the conclusion of the return thereof intoline-start position, and means actuated by said carriage for openingsaid circuit means to disconnect said auxiliary motor at an instantcoinciding with the engagement of said part of said carriage with saidbuffer.

11. A power-driven typewriter comprising a carriage which is advancedduring the typing operation, a carriage-return spring, means controlledby said carriage for tensioning said spring step-by-step during theadvance thereof so as to store in said spring power, to be utilized forreturning said carriage from an advanced position to line-startposition, an auxiliary motor, means controlled by said motor foraugmenting the power stored in said spring for the purpose of securingreturn of said carriage, circuit means for automatically connecting saidauxiliary motor for operating depending upon predetermined inclinationof said carriage to the horizontal so as to augment the force stored insaid spring in returning said carriage to line-start position, a shockabsorber having a yieldable buffer extending therefrom for engagement bya part of said carriage at the conclusion of the return thereof intoline-start position, and means actuated by said carriage for openingsaid circuit means to disconnect said auxiliary motor at an instantafter said part of said carriage has engaged said bufier.

12. A power-driven typewriter comprising a carriage which is advancedduring the typing operation, a carriagereturn spring, means controlledby said carriage for tensioning said spring step-by-step during theadvance thereof so as to store in said spring power, to be utilized forreturning said carriage from an advanced position to linestart position,an auxiliary fractional horse-power asynchronous motor, and meanscontrolled by said motor, acting independently of, but augmenting thepower stored in said spring for the purpose of securing return of saidcarriage.

13. A power-driven typewriter comprising a carriage which is advancedduring the typing operation, a carriagereturn spring, means controlledby said carriage for tensioning said spring step-by-step during theadvance thereof so as to store in said spring power, to be utilized forreturning said carriage from an advanced position to linestart position,an auxiliary fractional horse-power asynchronous motor, means controlledby said motor, acting independently of, but augmenting the power storedin said spring for the purpose of securing return of said carriage, acontrol element which is actuated to effect carriage return toline-start position, and circuit means controlled by said element forconnecting said auxiliary motor to its power source.

14. A power-driven typewriter comprising a carriage which is advancedduring the typing operation, a carriagereturn spring, means controlledby said carriage for tensioning said spring step-by step during theadvance thereof so as to store in said spring power, to be utilized forreturning said carriage from an advanced position to linestart position,an auxiliary fractional horse-power asynchronous motor, means controlledby said motor, acting independently of, but augmenting the power storedin said spring for the purpose of securing return of said carriage, acontrol element which is actuated to effect carriage return toline-start position, circuit means controlled by said element forconnecting said auxiliary motor for operation, and means controlled bysaid carriage for disconnecting said auxiliary motor from its powersource.

References Cited in the file of this patent UNITED STATES PATENTS

